/*  Starshatter OpenSource Distribution
    Copyright (c) 1997-2004, Destroyer Studios LLC.
    All Rights Reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name "Destroyer Studios" nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    SUBSYSTEM:    Stars.exe
    FILE:         CombatUnit.cpp
    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    A ship, station, or ground unit in the dynamic campaign.
*/

#include "MemDebug.h"
#include "CombatUnit.h"
#include "CombatGroup.h"
#include "Campaign.h"
#include "ShipDesign.h"
#include "Ship.h"

#include "Game.h"

// +----------------------------------------------------------------------+

inline double random() { return (double) rand() / (double) RAND_MAX; }

// +----------------------------------------------------------------------+

CombatUnit::CombatUnit(const char* n, const char* reg, int t, const char* d, int c, int i)
: name(n), regnum(reg), type(t), design_name(d), design(0),
count(c), iff(i), leader(false), dead_count(0), available(c),
carrier(0), plan_value(0), launch_time(-1e6), jump_time(0),
sustained_damage(0), target(0), group(0), heading(0)
{ }

CombatUnit::CombatUnit(const CombatUnit& u)
: name(u.name), regnum(u.regnum), type(u.type), design_name(u.design_name),
design(u.design), count(u.count), iff(u.iff),
dead_count(u.dead_count), available(u.available),
leader(u.leader), region(u.region), location(u.location),
carrier(u.carrier), plan_value(0), launch_time(u.launch_time),
jump_time(u.jump_time), sustained_damage(u.sustained_damage),
target(0), group(0), heading(u.heading)
{ }

// +----------------------------------------------------------------------+

const ShipDesign*
CombatUnit::GetDesign()
{
    if (!design)
    design = ShipDesign::Get(design_name);

    return design;
}

int
CombatUnit::GetShipClass() const
{
    if (design)
    return design->type;

    return type;
}

int
CombatUnit::GetValue() const
{
    return GetSingleValue() * LiveCount();
}

int
CombatUnit::GetSingleValue() const
{
    return Ship::Value(GetShipClass());
}

// +----------------------------------------------------------------------+

const char*
CombatUnit::GetDescription() const
{
    if (!design) {
        CombatUnit* pThis = (CombatUnit*) this; // cast-away const
        pThis->GetDesign();
    }

    static char desc[256];

    if (!design) {
        strcpy_s(desc, Game::GetText("[unknown]").data());
    }

    else if (count > 1) {
        sprintf_s(desc, "%dx %s %s", LiveCount(), design->abrv, design->DisplayName());
    }

    else {
        if (regnum.length() > 0)
        sprintf_s(desc, "%s-%s %s", design->abrv, (const char*) regnum, (const char*) name);
        else
        sprintf_s(desc, "%s %s", design->abrv, (const char*) name);

        if (dead_count > 0) {
            strcat_s(desc, " ");
            strcat_s(desc, Game::GetText("killed.in.action"));
        }
    }

    return desc;
}

// +----------------------------------------------------------------------+

bool
CombatUnit::CanLaunch() const
{
    bool result = false;

    switch (type) {
    case Ship::FIGHTER:
    case Ship::ATTACK:   result = (Campaign::Stardate() - launch_time) >= 300;
        break;

    case Ship::CORVETTE:
    case Ship::FRIGATE:
    case Ship::DESTROYER:
    case Ship::CRUISER:
    case Ship::CARRIER:  result = true;
        break;
    }

    return result;
}

// +----------------------------------------------------------------------+

Color
CombatUnit::MarkerColor() const
{
    return Ship::IFFColor(iff);
}

bool
CombatUnit::IsGroundUnit() const
{
    return (design && (design->type & Ship::GROUND_UNITS)) ? true : false;
}

bool
CombatUnit::IsStarship() const
{
    return (design && (design->type & Ship::STARSHIPS)) ? true : false;
}

bool
CombatUnit::IsDropship() const
{
    return (design && (design->type & Ship::DROPSHIPS)) ? true : false;
}

bool
CombatUnit::IsStatic() const
{
    return design && (design->type >= Ship::STATION);
}

// +----------------------------------------------------------------------+

double
CombatUnit::MaxRange() const
{
    return 100e3;
}

double CombatUnit::MaxEffectiveRange() const
{
    return 50e3;
}

double CombatUnit::OptimumRange() const
{
    if (type == Ship::FIGHTER || type == Ship::ATTACK)
    return 15e3;

    return 30e3;
}

// +----------------------------------------------------------------------+

bool CombatUnit::CanDefend(CombatUnit* unit) const
{
    if (unit == 0 || unit == this)
    return false;

    if (type > Ship::STATION)
    return false;

    double distance = (location - unit->location).length();

    if (type > unit->type)
    return false;

    if (distance > MaxRange())
    return false;

    return true;
}

// +----------------------------------------------------------------------+

double CombatUnit::PowerVersus(CombatUnit* tgt) const
{
    if (tgt == 0 || tgt == this || available < 1)
    return 0;

    if (type > Ship::STATION)
    return 0;

    double effectiveness = 1;
    double distance = (location - tgt->location).length();

    if (distance > MaxRange())
    return 0;

    if (distance > MaxEffectiveRange())
    effectiveness = 0.5;

    if (type == Ship::FIGHTER) {
        if (tgt->type == Ship::FIGHTER || tgt->type == Ship::ATTACK)
        return Ship::FIGHTER * 2 * available * effectiveness;
        else
        return 0;
    }
    else if (type == Ship::ATTACK) {
        if (tgt->type > Ship::ATTACK)
        return Ship::ATTACK * 3 * available * effectiveness;
        else
        return 0;
    }
    else if (type == Ship::CARRIER) {
        return 0;
    }
    else if (type == Ship::SWACS) {
        return 0;
    }
    else if (type == Ship::CRUISER) {
        if (tgt->type <= Ship::ATTACK)
        return type * effectiveness;

        else
        return 0;
    }
    else {
        if (tgt->type > Ship::ATTACK)
        return type * effectiveness;
        else
        return type * 0.1 * effectiveness;
    }

    return 0;
}

// +----------------------------------------------------------------------+

int
CombatUnit::AssignMission()
{
    int assign = count;

    if (count > 4)
    assign = 4;

    if (assign > 0) {
        available -= assign;
        launch_time = Campaign::Stardate();
        return assign;
    }

    return 0;
}

// +----------------------------------------------------------------------+

void
CombatUnit::CompleteMission()
{
    Disengage();

    if (count > 4)
    available += 4;

    else
    available += count;
}

// +----------------------------------------------------------------------+

void
CombatUnit::MoveTo(const Point& loc)
{
    if (!carrier)
    location = loc;
    else
    location = carrier->location;
}

// +----------------------------------------------------------------------+

void
CombatUnit::Engage(CombatUnit* tgt)
{
    if (!tgt)
    Disengage();

    else if (!tgt->attackers.contains(this))
    tgt->attackers.append(this);

    target = tgt;
}

void
CombatUnit::Disengage()
{
    if (target)
    target->attackers.remove(this);

    target = 0;
}

// +----------------------------------------------------------------------+

static int KillGroup(CombatGroup* group)
{
    int value_killed = 0;

    if (group) {
        ListIter<CombatUnit>  u_iter = group->GetUnits();
        while (++u_iter) {
            CombatUnit* u = u_iter.value();
            value_killed += u->Kill(u->LiveCount());
        }

        ListIter<CombatGroup> g_iter = group->GetComponents();
        while (++g_iter) {
            CombatGroup* g = g_iter.value();
            value_killed += KillGroup(g);
        }
    }

    return value_killed;
}

int
CombatUnit::Kill(int n)
{
    int killed = n;

    if (killed > LiveCount())
    killed = LiveCount();

    dead_count += killed;

    int value_killed = killed * GetSingleValue();

    if (killed) {
        // if unit could support children, kill them too:
        if (type == Ship::CARRIER ||
                type == Ship::STATION ||
                type == Ship::STARBASE) {

            if (group) {
                ListIter<CombatGroup> iter = group->GetComponents();
                while (++iter) {
                    CombatGroup* g = iter.value();
                    value_killed += KillGroup(g);
                }
            }
        }
    }

    return value_killed;
}

